Vania



N10.^.749,;o1 PATENTED :IA-r1.5, 1904.

K. RUsHToN.

- RELIABPfvALv-B PoR LoGoMoTIvBs'.'

APPLICATION FILED NOV. 23, 1903.

UNITED STATES Patented. anary 1904.

PATENT OFFICE.

KENNETH RUSHTON, OE PHILADELPHIA, PENNSYLVANIA, ASSIGNOR rlO BURNHAM, WILLIAMS & COMPANY, OE PHILADELPHIA, PENNSYL-- VAN'IA, A FIRM.

RELIEF-VALVE FOR LOCOMOTIVES.

SPECIFICATION forming part of Letters Patent N o. 749,101, dated January 5, 1904. Application filed November Z3, 1903.` Serial NO- 1821294- 'iNO mOdeLl -ments in relief-valves for locomotives which prevent Athe formation of a partial Vacuum in the low-pressure cylinder of a compound engine and the passages leading thereto and which also prevent the accumulation of steam in the low-pressure cylinder due to a leaky throttle.

Heretofore the relief-valve was 'carried by the valve controlling the flow of steam to and from the cylinders.

The object of my present invention is to so construct the device that the relief-valve will be stationary. This object I attain in the following manner, reference being had to the accompanying drawings, in Which- Figure 1 is a sectional View of sufficient of the saddle of a locomotive to illustrate my invention, and Fig. 2 is a sectional view illustrating a modication.

A is a portion of the saddle of a locomotive having the valve-chest B, in which reciprocates the piston-valve D, which I will term the cylinder-valve. This valve is connected to the valve-rod D', which extends through a stuing-box b in the forward cap B' and controls the iiow of steam to and from the cylinders.

S S are the steam-ports leading from the boiler.

H H are the ports leading from the highpressure cylinder.

L L are the ports leading from the low-pressure cylinder, and E is the exhaust-port.

The arrangement of the ports may differ, according to the type of engine to which my invention is applied.

The cylinder-valve D has a head d at the forward end and a head d at the rear end. d2 d2 are ports connecting with the interior of the valve, and d3 is an annular channel connecting with the exhaust-port. It Will be seen that the interior of the valve forms a passage to allow the steam to flow from the highpressure port on one side to the low-pressure porton the opposite side.

In the rear cap or cover-plate B2 is formed a chamber b2, which connects with the reliefvalve chest F and with the interior of the valve D through a tube b, whichis screwed into the cap B2 and extends through the stufting-box d4 in the head d' of the valve D. Any suitable packing d5 can be used in the box.

The relief-valve chest F has a stem f, which is screwed into the projection on the cap B2 and forms a communication with the chamber b2, and screwed into the valve-casing F is a cage f', which carries the valve-seat f2 for the valve G. Surrounding the cage is a cover F', secured to the cage by means of a nut f3 on the stem f4. When the valve is open, it rests upon the shoulder f5 on the valvecasing.

In Fig. 2 I'have shown a differentl form of relief-valve casing. The chamber in this instance is reduced, and the valve-inlet is on a line with the tube b. The valve-casing F2 has a seat fr', against which the valve G closes, and this valve is Asnpportedwhen open on a projection of the cap F3. Openings t" in the valvecasing allow for the ready inlet of air.

It will be seen by my improvement that the relief-valve is lixed in respect to the cylindervalve, and the projecting tubeb extends from the rear cap through a stuffing-box in the end of the cylinder-valve and communicates at all times with its interior, and consequently through the ports to the cylinders, Aand the locomotive can drift without creating a vacuum in the low-pressure cylinder or the passages leading thereto, as when. steam is cut oifthe relief-valve will open and air Will be drawn through the tube into the central portion of the cylinder-valve. This construction will prevent locomotives starting owing to leaky throttles, as the steam when it escapes will pass through the tube b and around the valve. It will be understood that the relief-valve in its normal position is open; but as soon as a quantity of steam is admitted to the valve-chest by opening the throttle the pressure will immediately close the reliefvalve G against its seat and hold itvthere during the normal working of the locomotive.

IOO

I claim as my invention- 1. The combination in a compound locomotive, of a valve-chest, a hollow cylindervalve therein controlling the flow of steam to and from the cylinders, a relief-valve xed to the chest and communicating with the interior of the said cylinder-valve, substantially as described.

2. The combination in a valve-chest having ports leading to the high and low pressure cylinders, a valve in said chest having a hollow center, a relief-valve carried by one of the caps closing the valve-chest, a tube extending from the cap and through one end of the cylinder-valve, and communicating with the relief-valve, substantially as described.

3. The combination in a valve-chesthavng ports communicating with the high and low pressure cylinders, a valve in said chest, said valve closed at each end forming a chamber, a cap closing the end of the valve-chest, a relief-valve carried by the said cap, a tube extending inwardly from the cap and through one end of the hollow valve so as to form a communication between the interior of the said valve and the relief-valve, one end of the hollow valve having a stuing-box through which the tube extends, substantially as described.

4. The combination in avalve-chest having ports leading to the high and low pressure cylinders, a hollow cylinder-valve having heads at each end, a cap closing the end of the valve-chest, a tube secured to said cap and extending through one end of the cylinder-valve, said cap having a chamber, a relief-valve casing communicating with said chamber, and a relief-valve in said casing, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

KENNETH RUSHTON.

Witnesses:

JAs. H. M. HAYES, W. N. TUTTLE. 

